Our goal is to create an affordable ventricular assist device, capable of meeting the needs of a broad range of patients with severe heart failure. The focus of this project will be to develop a miniature, low-cost, ventricular assist device, suitable for use for univentricular or biventricular support, for use as a bridge to recovery, transplant or a longer term implantable device. The specific design will feature a novel magnetically levitated configuration, whose key features allow rapid acceleration and deceleration in response to prescribed motor input power cycles. The major advantages of the current design are its small and relatively simple design, its ability to efficiently regulate pump output over a large range of flow conditions, and its ease of production. This program's overall goal will be to develop and optimize the design and construction of the magnetically levitated, centrifugal pump, and ascertain its physiological performance in vitro and in vivo. During Phase I of this project, in collaboration with the Texas Heart Institute, we demonstrated the soundness of this technology for both the adult and pediatric applications through a series of in vitro and in vivo experiments. In Phase II we intend to complete the design and validation of the product, and to launch device readiness testing in anticipation of clinical trials. The specific aims of this Phase II proposal are to: 1) Design and optimize the critical functional attributes of the pump system to meet cardiac support requirements. 2) Develop improved cannulae for ventricular assist device insertion. 3) Refine the design of the controller to operate over a broad range of pediatric and adult operating conditions, and to incorporate system alarms for fail-safe operation. 4) Conduct reliability testing of the controllers, motors and pumps to establish system confidence levels. 5) Demonstrate hemodynamic performance and biocompatibility for the proposed long-term VAD in an animal model. We believe that our technology, which provides effective ventricular assistance with a small, disposable device, may provide needed benefits to the health of a broad range of patients, while not adding significantly to the cost of caring for these patients. Achieving the aims proposed in this Phase II program will validate the safety and suitability of this device for evaluation under an IDE clinical trial, which will be carried out in a Phase III program. We project that in Phase III of the project we will meet the regulatory requirements governing an IDE, fabricate verified and validated hardware, establish reliability, and conduct indicated clinical trials.